heat treating question

[mudmarshal]

I found this information for heat treating 440C and ATS34. Please check through it and give me an opinion or suggestions on the temps and times.
440C
1500 for 20 min and air cool.
1875-1900 for 20 min and air cool.
Draw at 400 for 2 hrs and air cool. Repeat and air cool
ATS34
1500 for 20 min and air cool.
1900-1950 for 20 min and air cool.
Draw at 975 for 2 hrs and air cool. Repeat and air cool.

Another question I had deals with moving from one step to another in the heat treating sequence. I know that the blades should be let to cool down enough to be able to touch them. I need to know what is the max oven temp you can put the blades back in the oven. Meaning, how long do you have to wait on the oven to cool back down before starting on the next step?
Also, I was told to open the wrap as soon as the blades are removed from the oven. Will opening do or should the blades be removed from the wrap. I would think that at the temp the blades come out the less handeling the better because of warping.
I would appreciate any and all input.
Thank you and take care,
Robert

 

[Bruce Bump]

Robert this is what I have on the subject. It comes from Texas Knifemakers Supply with my Even Heat oven. For 440-c Preheat the oven to 1600 put the foil wrapped blade in hold at 1880 for 15 min. and remove. temper at 225 for 2 hours for 58 rc. For ATS-34 preheat oven to 1600 and put the foil wrapped blade in. Heat it to 1950 hold for 15 min. and remove. temper at 275 for 2 hours twice for 61 rc. 400 degrees for 2 hours twice for 58 rc I know some will temper at 975 with ATS and still get 60-61 rc. Both ways will work. I always remove the blades from the foil after a minute or so to prevent bending the glowing red hot blades while fumbling around getting the stupid foil opened. Bob Terzuola doesnt even take them out, He just blows the fan right on the foil. After you take them out they can be cooled by a fan until cool enough to handle and straighten if neccesary. Straighten them asap. Temper after totally cool and then Cryogenic after the first temper. I know there are other ways and if Paul Bos comes on here Im stepping aside but He has helped me learn what I know about the subject. Ive had pretty good luck too. I use the rockwell tester at the college and have had consistant results. Hope this helps.